Cook the pasta as per packet instructions - strain in colander and leave to cool in cold water.
Heat a wok to hot and add 1 tbsp of oil and cook the beef in 3 batches; set aside when cooked and loosely cover with aluminium foil.
Cook the sliced onions in the wok over low heat until soft and translucent. There’s no need to add oil.
In a bowl, mix the tomatoes, olives, onions, herbs, cooked beef and pasta; season with olive oil, balsamic vinegar and soy sauce. Just before serving, add rocket or mixed lettuce leaves.